The present invention relates to nursing bottles utilizing air pressure to expel air from disposable liners and the method of using such bottles for feeding an infant. A baby feeding from a nursing bottle often ingests air that is trapped in the liner of a nursing bottle. This air ends up in the baby""s stomach and can cause pain and regurgitation. The elimination of the air from the liner prevents the baby from ingesting the air and so reduces the possibility of the negative side effects associated with air in the baby""s stomach.
The problem of air in a disposable liner of nursing bottles has been recognized for some time. The prior art disclose devices that are used to eliminate air from the liner. For example, the prior art disclose the use of plungers, such as those disclosed in U.S. Pat. No. 5,524,783 to Popoff, U.S. Pat. No. 4,880,125 to LeBleau, and U.S. Pat. No. 3,648,873 to Grobbel. The end of the plunger is used to mechanically collapse the liner toward a nipple on the nursing bottles that cause a decrease in volume of the liner. As the liquid in the liner moves upward in response to the mechanical pressure from the plunger, the air in the liner is expelled through the nipple. A similar device is disclosed in U.S. Pat. No. 4,176,745 to Miller that has a pneumatic member that applies a force to a liner to expel air in the liner. The problem with all these devices is they require extra parts that are cumbersome to operate and an added expense to manufacture.
Other prior art disclosed in U.S. Pat. No. 5,687,861 to Wiedemann, and U.S. Pat. No. 5,921,426 to Randolph are simply, soft shell body nursers that when pressure is applied to the shell body, the shell body, because of direct contact, applies pressure to the liner, and forces the trapped air in the liner through the nipple. This works well only when the liner is full. When there is any volume of contents less than full, it is increasingly more difficult to squeeze. If either of these devices is placed to rest during the feeding, and air enters the liner it becomes very difficult, to almost impossible, to remove the air and continue feeding. The aperture in these devices, is for the sole purpose of allowing air to freely flow in and out between the liner and the shell body.
Prior art disclosed in U.S. Pat. No. 5,699,920 to Ida et.al. of which is the parent patent of this application, is the first soft nurser that when pressure is applied, air is removed from the liner. It, however, employs a valve that serves to make the air flow into the bottle automatic, a good, but not always necessary function that adds to the cost of manufacturing, and servicing over the life of use of the product.
Prior art disclosed in U.S. Pat. No. 2,804,995 to Fee and U.S. Pat. No. 4,020,978 to Szczepanski are basically container devices that dispense product, but do not teach, or even suggest, a benefit of feeding an infant with such a device. Also there is no suggestion or purpose of inherently limiting the use of these devices to adults only, by the application of multiple apertures.
Accordingly, it is an object of the present invention to teach the method of removing air from the liner prior to feeding, of a nursing bottle, providing a nursing bottle, especially intended for infants, which utilizes air pressure to collapse a liner and expel air from the liner via the nipple without the use of a valve, or any other mechanical parts.
It is another object of the present invention to provide a nursing bottle, which promotes upright feeding by keeping the nipple full of liquid during feeding.
It is another object of the present invention to provide nursing bottle that is easy to use, maintain, and operate.
It is a further object of the present invention to provide a nursing bottle that is economically and easily manufactured for widespread sale and use.
Certain of the foregoing and related objects are readily obtained in the following method of feeding an infant in which the method comprises the steps of providing a nurser comprising; a shell body having an open end and at least one aperture, a feeding nipple attachable to the open end of the body, a flexible liner suspendable from the open end of the body so as to create a chamber between the liner and the body, apertures apertures coverable by the operators hand, finger, or fingers for restricting the flow of air from the chamber, filling the liner with a liquid, covering aperture or apertures, squeezing the shell body until all the trapped air is forced out of the liner, and feeding the liquid through the nipple to the infant. Furthermore, the placement of multiple apertures, for the purpose of deterring a toddler from squirting the contents from the nurser, should be considered.